A former nanny and her father have pleaded not guilty to the killing of an Irish father-of-two in North Carolina and will argue they acted solely in self-defence.

The revelation came as the murder trial of Molly Martens Corbett (35) and her father, retired FBI agent Thomas Michael Martens (67), opened before Judge David Lee at Davidson County Superior Court in Lexington.

The trial opened with the selection process for a jury of 12 from a panel of 143 people.

All gathered in Courtroom C of the Davidson Superior Courts complex as temperatures soared across North Carolina.

Judge Lee said he expects the trial to last between two and three weeks, or possibly even longer.

The father and daughter are charged with the second-degree murder of Limerick father Jason Corbett (39) two years ago.

A second charge of voluntary manslaughter has been withdrawn by the prosecution.

Ms Martens Corbett appeared in court wearing a grey blazer and blue dress while her father wore a dark blue suit.

Neither spoke during the hearing but both were asked to stand to identify themselves to the jury panel.

Judge Lee said that, to help expedite the jury selection process, the entire 143-strong jury panel would be asked to complete a detailed 16-page questionnaire. This included a list of all potential witnesses in the trial. "You will try to find the truth and reach a verdict or verdicts in this case," Judge Lee said. "You alone will determine the truth."

Judge Lee noted that the jurors did not volunteer and were randomly chosen by the Davidson County Jury Commission.

Qualifying jurors must be aged 18 or over, must be English speaking, be citizens of both North Carolina and Davidson County and must not be disqualified from serving on a jury through any convictions.

Jurors were also told they should indicate if they had previously heard or read about the trial matters involved. Once the selection process concludes, Greg Brown will open the case for the prosecution.

Mr Corbett was found lying in a pool of blood with fatal head injuries, on August 2, 2015, in the Panther Creek home at the Meadowlands complex where he relocated with his children to build a new life with his second wife, Molly. Mr Corbett's first wife, Margaret 'Mags' Fitzpatrick, who suffered from asthma all her life, died in November 2006, from a severe attack of the illness. Her husband was just 30 when she died, and their children were aged just two and three months.

Mr Corbett met Ms Martens in 2008 when he advertised for an au pair nanny to help him raise his two children, Jack and Sarah.

Ms Martens, who hailed from outside Knoxville in Tennessee, replied to the advert and moved to Ireland to help look after the children. A relationship eventually developed between Mr Corbett and Ms Martens, and they married in 2011. Because she was homesick for the US, Mr Corbett decided to relocate.

His employers arranged for him to transfer to a plant they operated in North Carolina.

However, Davidson County police received an emergency call in the early hours of August 2, 2015, saying Mr Corbett had sustained serious head injuries.

He was pronounced dead shortly after paramedics attended the scene.

Mr Martens was visiting his daughter and son-in-law that weekend. In pre-trial submissions it emerged Mr Martens claimed he only struck Mr Corbett with a baseball bat after intervening in a row between the couple. He will claim he went upstairs after hearing shouting. His legal team will also argue he acted in self-defence because he feared for the life of his daughter and himself.

Fatal

The district attorney is represented by three lawyers, Greg Brown, Alan Martin and Ina Stanton. Both Mr Marten and his daughter have two lawyers, David Freedman and Jones Byrd together with Walter Holton and Cheryl Andrews.

Prosecutors will argue the fatal incident occurred against a backdrop of Mr Corbett wishing to move back to Ireland with his children but without Ms Martens. A major custody battle erupted immediately after Mr Corbett's death in 2015, before the US authorities allowed Mr Corbett's family to bring the children to Ireland. The children are now in the care of Mr Corbett's sister, Tracey Lynch, and her husband, David.

Members of the Corbett family attended the jury selection process yesterday.

A number of relatives and friends of the Martens, including Mr Martens' brother-in-law, Michael, also attended.

Ms Martens had wanted the children to remain in the US with her. Since 2015, she has posted multiple social media messages to the children.

One message, posted on Facebook, said: "I miss you with every single heartbeat."